10 Smartphone Apps that Threaten Your Privacy without You Knowing

Our daily lives are filled with subtle threats to our privacy, often without us even realizing it. In my 2021 blog post, “Four Mistakes That Could Undermine Your Privacy,” I discussed some of these hidden risks. That same year, I also wrote “I’m Sticking with WhatsApp: Here’s Why?” in response to the mass exodus of WhatsApp users to Signal, driven by a misunderstanding of Meta’s privacy policy changes, which mainly affected WhatsApp Business users. Both posts highlight how people either take their privacy for granted or overreact without fully understanding the situation. Today’s blog post was inspired by the discovery of ten major smartphone apps that unknowingly jeopardize our privacy. These apps often collect more data than we realize. In this post, I’ll walk you through these privacy risks and suggest safer alternatives. Keep reading to see if you’re using any of these apps and how to protect your privacy more effectively.

Note: These apps threaten Android users more due to looser privacy controls. Apple enforces stricter policies, but iOS users should still be cautious.

Truecaller: The Phonebook You Never Signed Up For

When my father got his first Fixed Line from Sri Lanka Telecom in the early 90s, there was no CLI feature. Fast forward to 2025, and with Truecaller, we can not only see the caller’s number but even their name. While marketed as a caller ID and spam-blocking app, Truecaller raises serious privacy concerns. The app uploads your entire contact list, making private numbers searchable without consent. Even if you’ve never used it, your number could be in its system if someone saved it. It also collects call and SMS metadata, tracking who you contact, when, and how often. Removing your number is difficult, requiring an online request. Though Truecaller claims to anonymize data, its history of sharing user info with third parties is concerning. If privacy matters to you, consider alternatives like Hiya or Simple Dialer, which offer caller ID without invasive data collection.

Caution: Hiya and Simple Dialer are safer alternatives, with Simple Dialer not collecting call metadata. However, it’s important to regularly review their privacy policies, as data practices may change.

Shazam: Always Listening, Even When You’re Not

When I first learned about Pegasus, I was concerned, but little did I know that Shazam is always listening, even when not in use. Shazam, a popular music recognition app, continuously accesses the microphone, raising concerns about background listening and potential eavesdropping. A malware could leverage this function for its own advantage. The app also collects location data, device IDs, and browsing history for targeted ads and sharing with third parties. While Apple’s acquisition of Shazam promises improved privacy, the risk of data collection (which Apple may use to improve its services) remains. If you’re looking for a safer alternative, try AHA Music, a browser-based service that doesn’t require microphone access or app installation. To further protect your privacy, be cautious with microphone permissions and disable background app activity to reduce unwanted data collection.

Caution: AHA Music is a web app, not a smartphone app. Nevertheless, always review its privacy policy to understand data practices and limit unnecessary permissions for your privacy.

Cleaner Apps: The Digital Snake Oil of Smartphones

Android devices tend to slow down faster than iOS, leading users to install “Cleaner Apps” like CCleaner, DU Speed Booster, and Clean Master. These apps claim to boost performance but often do more harm than good. Many acts as data harvesters, collecting personal information, browsing habits, and device details. Some have even been caught injecting malware or adware, further slowing down phones. Worse, they demand excessive permissions, including access to call logs, messages, and location data. Instead of using these invasive apps, try Files by Google, which safely manages storage without collecting unnecessary personal data. Be cautious of apps promising magical performance boosts—most exist to exploit user data for advertising revenue. The best way to keep your phone running smoothly is to manage storage manually and avoid apps that demand unnecessary access to your data.

Caution: While Files by Google is safer than most cleaner apps, it still collects some data, as Google’s business model relies on advertising.

Free PDF Scanners: Your Documents are Not Yours

In the 1990s, a flatbed scanner cost between 50,000 – 150,000 rupees. Today, scanning documents is far more affordable, with many free PDF scanner apps like CamScanner widely used to digitize documents. However, most users don’t realize these apps often upload scanned files to remote servers, risking exposure of sensitive personal or business information. CamScanner was even removed from the Google Play Store after being caught distributing malware. Other PDF scanner apps have been found sharing user data with advertisers, putting scanned IDs, contracts, and personal notes at risk. For a safer alternative, use Microsoft Lens or OpenScan, which prioritize privacy and do not upload documents to third-party servers. Also, always check app permissions—if a scanner app requests internet access or excessive permissions, it may be doing more than just scanning.

Caution: It’s wise to regularly review the privacy policies of Microsoft Lens and OpenScan, as their data practices may change over time.

Free Mobile Games: Data Harvesters in Disguise

I remember uninstalling a game in the late 90s because it demanded too many system resources. Fast forward to 2025, and while gaming has evolved, many smartphone games come with hidden privacy risks. Popular free titles like Angry Birds and Subway Surfers secretly collect vast amounts of user data, often requesting unnecessary permissions like location tracking, microphone access, and contact list access. Developers sell this data to advertisers, creating detailed user profiles that extend beyond gaming habits. Some games have even been linked to government surveillance programs. Even children’s games aren’t safe—many have been caught violating privacy laws by collecting data on underage users. To protect your privacy, always review permissions before installing a game. Consider open-source or premium games that don’t rely on intrusive tracking. If a game asks for excessive access to your personal data, it’s best to avoid it altogether.

Weather Apps: More Than Just a Forecast

Weather apps like AccuWeather and WeatherBug do more than just tell you if it’s going to rain—they track your location and sell that data to third parties. AccuWeather, in particular, has been caught collecting and sharing user location data even when location services were disabled. Many weather apps use your location to serve targeted ads, but some go further by selling movement patterns to data brokers, who then resell it to advertisers or even government agencies. If you value your privacy, switch to Weawow, a privacy-focused weather app that does not track users or sell their location data. Alternatively, you can rely on built-in weather apps on iOS or Android, which provide accurate forecasts without invasive tracking. Always be mindful of which apps request access to your location and deny unnecessary permissions.

Caution: While Weawow prioritizes user privacy, regularly reviewing its privacy policy is essential, as data practices can change over time.

Free VoIP & Call Recording Apps: Who’s Listening?

Many free VoIP and call recording apps, such as Dingtone, TextNow, and various call recorder apps, come with significant privacy risks. These apps often log call metadata, store recordings on their servers, and sometimes even share data with third parties. Some have been found selling user data to advertising networks, making your private conversations a potential goldmine for marketers. Others lack proper security measures, leaving recordings vulnerable to breaches. If you need a secure VoIP solution, consider using JMP.chat, which prioritizes privacy and encryption (May not be available in all regions). For call recording, look for apps with local storage options rather than cloud-based storage. Always review app privacy policies before downloading and be cautious of any communication app that requires excessive permissions, such as access to contacts, messages, or storage, without a clear reason.

Keyboard Apps: The Silent Data Thieves

I love custom keyboard apps like Microsoft Swift Key. However custom keyboard apps like Kika Keyboard, GO Keyboard, and ai.type offer fun themes and emojis, but they come with hidden dangers. Many of these apps have been caught logging every keystroke, meaning they could record sensitive data such as passwords, credit card numbers, and private messages. Some keyboard apps also collect personal data and send it to remote servers, posing a significant security risk. In some cases, leaked user databases from these apps have exposed millions of keystroke logs. To stay safe, stick with Gboard (Google’s Keyboard, which has minimal tracking) or OpenBoard, an open-source alternative that prioritizes privacy. Always be cautious when installing a keyboard app—if it requests internet access without a clear reason, it might be sending your keystrokes to external servers.

Face & Voice-Changing Apps: Fun at a Cost

Face-altering and voice-changing apps like FaceApp, Voicemod, and YouCam may seem harmless, but they often collect biometric data, including facial scans and voice recordings. Many of these apps store this data on remote servers, and in some cases, it’s unclear how long the data is retained or who has access to it. FaceApp, for instance, raised global concerns over its ties to Russian servers [Full Story], leading to fears about data misuse. Some of these apps also share data with third-party advertisers, making your biometric information a valuable commodity. If you enjoy using such apps, opt for ones with clear privacy policies and local data processing. Alternatively, use built-in phone filters or offline software that doesn’t rely on cloud storage to reduce the risk of biometric data being exploited. Even better, avoid such apps entirely.

Free VPNs: The Biggest Privacy Scam

The late David Kernell, who hacked Sarah Palin’s Yahoo! email account in 2008, used a proxy server to hide his tracks. However, CTunnel.com logged his IP address and cooperated with the FBI, leading to his identification. Likewise, many free VPN services, such as Hola VPN, Turbo VPN, and SuperVPN, claim to protect your privacy but actually do the opposite. Instead of encrypting your data securely, these VPNs often log your browsing activity and sell it to third parties. Some have even been caught injecting ads into websites or exposing users to serious security vulnerabilities. Free VPNs often have vague privacy policies, making it unclear who controls your data or where it’s stored. If you need a reliable VPN, opt for a trusted, no-logs provider like Mullvad, ProtonVPN, or IVPN, which prioritize user security and have been independently audited. If you’re tech-savvy, you can even build your own VPN server.

Wrap Up

In an era where convenience often comes at the cost of privacy, it’s crucial to be mindful of the apps we install and the data we share. Many free apps, whether for communication, gaming, scanning, or even weather updates, operate on a hidden business model—harvesting user data for profit. While Apple enforces stricter privacy policies, iOS users are not entirely safe either. Android users, in particular, should exercise caution due to looser app regulations. The best defense against invasive apps is awareness. Always check app permissions, research privacy policies, and consider privacy-respecting alternatives. In some cases, opting for open-source software or premium apps can provide better security without hidden trade-offs. Ultimately, protecting your digital privacy requires a proactive approach—because once your data is out there, you have little control over how it’s used. Stay informed, stay cautious, and choose your apps wisely.

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